基于有机单晶的自旋电子器件

This project proposed here aims to fabricate and characterize fully functional spin devices with an active layer of organic single crystalline materials. To increase the chances of success to produce such a device and also lead to more results and a better understanding of the spin-ralated properties in these devices, vertical and lateral device structures will be employed with solvent-based and physical vapour deposition methods. Once devices are working, it shall be differentiated between the two major operation modes of spintronics devices, quantum tunnelling and spin injection/diffusion. This differentiation will be conducting by studying these devices as a function of the thickness of the organic single layer. In addition, by using for instance rubrene ortetramethyltetraselenafulvalene (TMTSF), thermally activated and band-like transport of the spin-carrying charge carriers could be distinguished, hence demonstrating those clear transport regimes for the first time. With an increasing mobility combined with a diminished spin decoherence for lower termetatures, device performance will be tremendously improved through band-like transport observation with lateral device structures. Finally, the produced single crystals will be investigated with the so-called muon spin relaxation(muSR) technique which allows for the determination of the electron spin relaxation rate in these materials at a local level. The single crystalline morphology enables the measurement of well-defined spin relaxation rates in these materials including the anisotropic components of the spin relaxation because each molecule in the crystal is exposed to an identical environment. This project will obtain better defined parameters in the device physics than in the amorphous case such as the magnetoresistance and general trends, thus offering enormous potential for future investigations of the spin properties in organic materials and its combination with other crystalline materials.

本研究课题提出利用有机单晶材料的活跃层组装实现全功能型自旋器件。为了提高成功率以及增进对该器件中自旋相关特性的研究，在基于溶剂和物理气相沉积方法中将使用纵向与横向器件结构。器件一旦完成并可以运行，通过研究器件跟有机单层厚度的依赖关系，我们将能区分自旋电子器件的量子隧穿与自旋注入/扩散两种主要运作模式。利用如ＴＭＴＳＦ，能够区分自旋载流子的热激发与带状运输，进而首次证明已知的输运机制。迁移率增加伴随着更低温时自旋退相干减弱，用横向器件结构进行的带状输运观测将有助大幅提升器件的性能。利用利用局域水平下探测电子自旋弛豫率的μ介子自旋弛豫技术来研究所生长的单晶。获得的磁阻参数和器件物理中运作模式的转变的一般趋势将是比无定型结构的例子更好的结果，因此，本项目将为未来的像基于有机单晶的自旋电子器件等的研究项目提供了巨大的潜能，并且还将使有机材料或者其他晶体材料中自旋特性的基础研究更加深入。

通过电子自旋来实现信息的传输将有可能带来一场信息产业的革命，而有机材料的自旋电子器件对于自旋电子学有非常重要的研究意义。是目前国际研究的热点。该项目利用超长的篇幅介绍了利用有机单晶（而不是非晶或其它）制备全功能型自旋电子器件。用有机单晶制备器件将会对自旋电子输运的两个重要过程和机理，量子隧穿和自旋注入和扩散加以分辨。申请人在对研究现状充分调研的基础上，提出利用有机单晶材料的活跃层组装实现全功能型自旋器件，研究目标明确，研究内容创新性强；研究方案详细、合理、可行；申请人在相关领域积累了一定经验，且做了一些前期工作，取得了有价值的研究成果，具有很好的研究基础；研究队伍和经费预算都比较合理。曾在Nature Materials上发表过第一作者论文。四川大学也为本项目的实施提供完善的条件。自旋电子学是未来微电子发展的重要领域之一，项目具有重要的科学意义和前沿性，其器件的结构和有机材料的制备等都具有一定难度和不确定性。与此同时，器件的自旋特性测试和表征也是目前自旋研究的.重点和难点。